Function get_cpu_kernel

src/test/test_kernelmatrix.cpp:26–67

}

kernel_type get_cpu_kernel(const DataSet::node2d &instances, int x, int y, const SvmParam &param) {
    kernel_type r;
    switch (param.kernel_type) {
        case SvmParam::RBF: {
            float_type sum = 0;
            auto i = instances[x].begin();
            auto j = instances[y].begin();
            while (i != instances[x].end() && j != instances[y].end()) {
                if (i->index < j->index) {
                    sum += i->value * i->value;
                    i++;
                } else if (i->index > j->index) {
                    sum += j->value * j->value;
                    j++;
                } else {
                    sum += (i->value - j->value) * (i->value - j->value);
                    i++;
                    j++;
                }
            }
            while (i != instances[x].end()) {
                sum += i->value * i->value;
                i++;
            }
            while (j != instances[y].end()) {
                sum += j->value * j->value;
                j++;
            }
            r = expf(-param.gamma * sum);
            break;
        }
        case SvmParam::POLY:
            r = powf(param.gamma * dot_product(instances, x, y) + param.coef0, param.degree);
            break;
        case SvmParam::LINEAR:
            r = dot_product(instances, x, y);
            break;
        case SvmParam::SIGMOID:
            r = tanhf(param.gamma * dot_product(instances, x, y) + param.coef0);
    }
    return r;
}

class KernelMatrixTest : public ::testing::Test {
    DataSet dataSet;